Physical and Electrochemical Characterizations of Microwave-Assisted Polyol Preparation of Carbon-Supported PtRu Nanoparticles

摘要

PtRu nanoparticles supported on Vulcan XC-72 carbon and carbon nanotubes were prepared by a microwave-assisted polyol process.The catalysts were characterized by transmission electron microscopy,X-Ray diffraction,and X-ray photoelectron spectroscopy(XRS).The PtRu nanoparticles,which were uniformly dispersed on carbon,were 2-6 nm in diameter.All PtRu/C catalysts prepared as such displayed the characteristic diffraction peaks of a Pt face-centered cubic structure,excepting that the 20 values were shifted to slightly higher values.XPS analysis revealed that the catalysts contained mostly Pt(O)and Ru(O),with traces of Pt(II),Pt(IV),and Ru(IV).The electro-oxidation of methanol was studied by cyclic voltammetry,linear sweep voltammetry,and chronoamperometry.It was found that both PtRu/C catalysts had high and more durable electrocatalytic activities for methanol oxidation than a comparative Pt/C catalyst.Preliminary data from a direct methanol fuel cell single stack test cell using the Vulcan-carbonsupported PtRu alloy as the anode catalyst showed high power density.